Apparatus for recording and/or reproducing disc-shaped recording medium

ABSTRACT

To reduce the weight and size of the whole apparatus by decreasing the number of motors as driving sources and to reduce the manufacturing cost. The apparatus comprises: a plurality of disc trays each on which an optical disc is placed; a tray stocker in which the disc trays are stacked and housed; an elevating mechanism for elevating the tray stocker; an optical pickup device and a disc rotating mechanism for performing recording or reproduction; a tray carrying mechanism for moving a disc tray between a stock position and a play position; a driving motor for driving both the carrying mechanism and the elevating mechanism; and a switching mechanism for selectively supplying a driving force from the driving motor to the carrying mechanism and the elevating mechanism.

TECHNICAL FIELD

[0001] The present invention relates to an apparatus for recordingand/or reproducing a disc-shaped recording medium, which records orreproduces an information signal by using an optical disc such as a CD(compact disc) or a CD-ROM (read-only memory), a disc-shaped recordingmedium such as a magneto optical disc, or the like. More particularly,the invention relates to an apparatus for recording and/or reproducing adisc-shaped recording medium, which can selectively switch an operationof elevating a housing member for housing a plurality of placementmembers each on which a disc-shaped recording medium is placed and anoperation for carrying any one of a plurality of placement members atleast between a position where the placement member is housed in thehousing member and a position where a disc-shaped recording medium isloaded to a recording and/or reproducing unit.

BACKGROUND ART

[0002] Conventionally, generally, as an example of an apparatus forrecording and/or reproducing a disc-shaped recording medium, there hasbeen provided a disc recording and/or reproducing apparatus forreproducing music, movie, or the like by using a disc-shaped recordingmedium such as a CD or CD-ROM. As a disc recording and/or reproducingapparatus of this kind, for example, a disc player 1 as shown in FIG. 1is known.

[0003] The disc player 1 has the function of, for example, housing threedisc cartridges 2 at once, consecutively reproducing the three discshoused in the disc cartridges 2 and reproducing music pieces recorded ondiscs housed in the three disc cartridges 2 in accordance with anarbitrary order. The disc player 1 comprises a changer 3 capable ofhousing the three disc cartridges 2, a carrying mechanism for selectingand carrying an arbitrary disc cartridge 2 between the changer 3 and adisc driving device, and a recording/reproducing mechanism for chuckingthe disc cartridge 2 carried by the carrying mechanism and recording orreproducing music or the like.

[0004] The changer 3 is mounted in the central part of the front face ofthe device body 4 and has three cartridge insertion ports 5 a, 5 b, and5 c on its front face. The three cartridge insertion ports 5 a to 5 care arranged at predetermined intervals in the vertical direction(three-layer structure). On one sides of the cartridge insertion ports 5a to 5 c, ejection buttons 6 a, 6 b, and 6 c for ejecting the disccartridges 2 inserted in the corresponding cartridge insertion ports 5 ato 5 c are provided, respectively.

[0005] The front face of the changer 3 is covered with a door 7 attachedto the front side of the device body 4. On both sides of the door 7, anumber of operation buttons 8 such as a power button for turning on/offthe power source, a feed button, and a stop button are arranged. Whenthe door 7 is opened to expose the front face of the changer 3 and thedisc cartridges 2 are inserted from the cartridge insertion ports 5 a to5 c, the three disc cartridges 2 are housed and held in predeterminedpositions.

[0006] Behind the changer 3, a carrying mechanism for selectively takingand carrying arbitrary one of the three disc cartridges 2 housed inpredetermined positions is provided. Near the carrying mechanism, a discreproducing device for chucking the disc as a recording medium of thedisc cartridge 2 supplied by the carrying mechanism and loaded in apredetermined position, reading a sound signal or the like, andreproducing music or the like is disposed.

[0007] In the conventional disc player 1 as described above, however,three motors are used as driving sources; a motor for vertically movinga holder for selectively taking out an arbitrary disc cartridge 2 fromthe three disc cartridges 2 housed in cartridge housing parts in threepositions, a motor for carrying a cartridge holder for holding the takendisc cartridge 2 to the disc reproducing device, and a motor forchucking the disc cartridge 2 supplied to the disc reproducing deviceand rotating it at predetermined speed. Since an independent motor isused for each of the operations such as ejection of the disc cartridge,carriage of the disc cartridge, and the like, there are problems suchthat the number of motors used is large, the whole device is heavy, andit is uneconomical.

[0008] Ditto for a disc player using a disc-shaped recording medium suchas a CD in place of the above-described disc cartridge 2. The discplayer of this kind is provided with a plurality of disc trays on whicha plurality of CDs are placed, respectively, and a tray stocker forholding the plurality of disc trays. As driving sources of thosecomponents, total three motors are used; a motor for vertically movingthe tray stocker, a motor for ejecting the disc trays held by the traystocker from the device body and carrying a CD placed on the disc trayto the disc reproducing unit, and a motor for moving a spindle motor inthe disc reproducing unit and chucking the CD. The disc player also hasthe three motors and, likewise, the number of motors is large.

[0009] The inventor who applies for the present invention has completeda mechanism capable of performing the above-mentioned three kinds ofoperations by two motors. According to the mechanism, both the operationof vertically moving the tray stocker for holding the plurality of disctrays and the carrying operation of tacking and carrying one of the disctrays held in the tray stocker can be performed by a single motor. Theinventor had made efforts to realize an operation of exchangingdisc-shaped recording media during recording or reproducing of adisc-shaped recording medium by using a single motor as a driving sourceand could have invented an exchange mechanism having such a function.

[0010] In the exchange mechanism, however, whether the disc-shapedrecording medium is placed on the disc placement part of the disc trayor not has to be sensed. An optical sensor is therefore disposed insideof the front face of the device body and the presence or absence of thedisc-shaped recording medium is determined according to whether lightemitted from the optical sensor is interrupted or not. Since the opticalsensor is disposed near the recording medium insertion port, there is acase that external light enters the device body and it causes a problemsuch that the presence/absence of the disc-shaped recording medium iserroneous determined due to the influence of external light.

[0011] Further, since a wiring board, operation buttons an otherelectronic parts mounted on the wiring board, a display panel, and thelike are disposed where the optical sensor is mounted, those componentsinterfere with the optical sensor. It brings about a problem such thatdesigning of the disc recording/reproducing apparatus is limited.

[0012] In the exchanging mechanism, a power transmission path connectinga feed gear to be engaged with a rack formed in the disc tray and themotor for driving the feed gear so as to transmit the power is directlyconnected. Since the driving force of the motor is directly transmittedfrom the feed gear to the rack, it causes the following problem. Thereis the possibility that the disc tray erroneously is moved due to therotation of the motor during recording or reproduction of the disc-shaperecording medium.

[0013] The invention has been achieved in consideration of theconventional problems and an object of the invention is to provide anapparatus for recording and/or reproducing a disc-shaped recordingmedium, whose weight and size are reduced by decreasing the number ofmotors as driving sources and also whose manufacturing cost is reduced,thereby solving the problems.

[0014] Further, an object of the invention is to provide an apparatusfor recording and/or reproducing a disc-shaped recording medium, whichcomprises a photodetector almost in a center of a position where a disctray housed in a housing part is housed and which can detect thepresence or absence of a disc-shaped recording medium by turning on oroff light from the photodetector by the disc-shaped recording mediumbeing carried without causing an erroneous decision due to an influenceof external light and increase the degree of freedom in designing byreducing limitation on designing, thereby solving the problems.

[0015] Further, an object of the invention is to provide an apparatusfor recording and/or reproducing a disc-shaped recording medium, capableof realizing an exchanging function with a simple structure bydisconnecting the power transmitting path during recording orreproduction of a disc-shaped recording medium so as not to transmit adriving force to a feed gear, thereby solving the problems.

DISCLOSURE OF THE INVENTION

[0016] An apparatus for recording and/or reproducing a disc-shapedrecording medium according to the invention comprises: a plurality ofplacement members on each of which a disc-shaped recording medium isplaced; a housing unit in which the placement members are stacked andhoused; an elevating mechanism for elevating the housing unit in thedirection almost parallel to the stack direction of the placementmembers; a recording and/or reproducing unit for recording orreproducing the disc-shaped recording medium; a carrying mechanism forcarrying at least one of the plurality of placement members between aposition where the placement member is housed in the housing unit and aposition where the disc-shape recording medium placed on the placementmember is loaded to the recording and/or reproducing unit; a drivingsource for driving both the carrying mechanism and the elevatingmechanism; and a switching mechanism for selectively supplying a drivingforce from the driving source to the carrying mechanism and theelevating mechanism.

[0017] Further, an apparatus for recording and/or reproducing adisc-shaped recording medium according to the invention comprises: aplurality of placement members on each of which a disc-shaped recordingmedium is placed; a housing unit in which the placement members arestacked and housed; an elevating mechanism for elevating the housingunit in the direction almost parallel to the stack direction of theplacement members; a recording and/or reproducing unit for recording orreproducing the disc-shaped recording medium; a carrying mechanism forcarrying one of the plurality of placement members among a positionwhere a disc-shaped recording medium can be placed or ejected to/fromthe placement member, a position where the placement member is housed inthe housing unit and a position where the disc-shape recording mediumplaced on the placement member is loaded to the recording and/orreproducing unit; a driving source for driving both the carryingmechanism and the elevating mechanism; and a switching mechanism forselectively supplying a driving force from the driving source to thecarrying mechanism and the elevating mechanism.

[0018] Further, an apparatus for recording and/or reproducing adisc-shaped recording medium according to the invention comprises: aplurality of placement members on each of which a disc-shaped recordingmedium is placed; a housing unit in which the placement members arestacked and housed; a recording and/or reproducing unit for recording orreproducing the disc-shaped recording medium; a moving mechanism formoving the recording and/or reproducing unit from a position where thedisc-shaped recording medium on the placement member is lifted from theplacement member and a position lower than the placement member; acarrying mechanism for carrying one of the plurality of placementmembers between a position where the placement member is housed in thehousing unit and a position where the disc-shape recording medium placedon the placement member is loaded to the recording and/or reproducingunit; a driving source for driving the carrying mechanism; and atransmitting mechanism for interrupting transmission of a driving forcefrom the driving source when the recording and/or reproducing unit ismoved to the lifting position.

BRIEF DESCRIPTION OF DRAWINGS

[0019]FIG. 1 is a perspective view showing an example of a conventionalapparatus for recording and/or reproducing a disc-shaped recordingmedium.

[0020]FIG. 2 is a perspective view showing an example of an apparatus ofthe invention for recording and/or reproducing a disc-shaped recordingmedium in a state where components are disassembled block by block.

[0021]FIG. 3 is a perspective view showing an example of an apparatus ofthe invention for recording and/or reproducing a disc-shaped recordingmedium in a state where components are disassembled.

[0022]FIG. 4 is a perspective view showing a chassis assembly and astocker assembly in an example of an apparatus of the invention forrecording and/or reproducing a disc-shaped recording medium.

[0023]FIG. 5 is a plan view showing a state where a plurality of disctrays are stocked in a tray stocker in positions where disc trays arehoused in an example of an apparatus of the invention for recordingand/or reproducing a disc-shaped recording medium.

[0024]FIG. 6 is a cross section taken along X-X line of the apparatusfor recording and/or reproducing a disc-shaped recording mediumaccording to the invention shown in FIG. 4.

[0025]FIG. 7 is a cross section taken along Y-Y line of the apparatusfor recording and/or reproducing a disc-shaped recording mediumaccording to the invention shown in FIG. 4.

[0026]FIG. 8 is a vertical section showing a state where the traystocker of the apparatus of the invention for recording and/orreproducing a disc-shaped recording medium is elevated to the uppermoststage.

[0027]FIG. 9 is a plan view showing a state where the disc tray of theapparatus of the invention for recording and/or reproducing adisc-shaped recording medium is moved to a position where thedisc-shaped recording medium can be placed or ejected.

[0028]FIG. 10 is a plan view showing a state where the disc tray of theapparatus of the invention for recording and/or reproducing adisc-shaped recording medium is moved to a position where thedisc-shaped recording medium placed on the disc tray is loaded into arecording and/or reproducing unit.

[0029]FIG. 11 is a plan view showing a state where a disc tray of anapparatus of the invention for recording and/or reproducing adisc-shaped recording medium is moved to a position where a disc-shapedrecording medium placed on the disc tray is loaded into a recordingand/or reproducing unit, and the recording and/or reproducing unit ismoved to a position where the disc-shaped recording medium is liftedfrom a placement member.

[0030]FIG. 12 is a plan view showing a state where the disc tray of theapparatus of the invention for recording and/or reproducing adisc-shaped recording medium has been moved in a position where thedisc-shaped recording medium can be placed or ejected during recordingor reproduction.

[0031]FIG. 13 is a perspective view showing the disc tray of theapparatus of the invention for recording and/or reproducing adisc-shaped recording medium.

[0032]FIG. 14 is an explanatory diagram showing the disc trays of theapparatus of the invention for recording and/or reproducing adisc-shaped recording medium so as to compare with conventional disctrays.

[0033]FIG. 15 is a perspective view showing a tray stocker of theapparatus of the invention for recording and/or reproducing adisc-shaped recording medium.

[0034]FIG. 16 is a perspective view showing a sliding member of theapparatus of the invention for recording and/or reproducing adisc-shaped recording medium.

[0035]FIG. 17 is a plan view showing a power transmitting path of theapparatus of the invention for recording and/or reproducing adisc-shaped recording medium.

[0036]FIG. 18 is a partly sectional side view showing a powertransmitting path of a disc tray carrying system of the apparatus of theinvention for recording and/or reproducing the disc-shaped recordingmedium.

[0037]FIG. 19 is a partly sectional side view showing the powertransmitting path of a chucking operation system of the apparatus of theinvention for recording and/or reproducing a disc-shaped recordingmedium.

[0038]FIG. 20 is a partly sectional side view showing the powertransmitting path of a sliding member driving system of the apparatus ofthe invention for recording and/or reproducing a disc-shaped recordingmedium.

[0039]FIG. 21 is a cross section showing a main part of the powertransmitting path in the disc tray carrying system of the apparatus ofthe invention for recording and/or reproducing a disc-shaped recordingmedium.

[0040]FIG. 22 is a partly sectional perspective view of a steppedswitching lever and an elevating gear of the apparatus of the inventionfor recording and/or reproducing a disc-shaped recording medium.

[0041]FIG. 23 is an explanatory diagram for explaining the positionalrelation between the disc tray and a photodetector of the apparatus ofthe invention for recording and/or reproducing a disc-shaped recordingmedium, in which FIG. 23A shows that the disc tray is in a positionwhere the disc-shaped recording medium is housed in the housing part,FIG. 23B shows that the disc tray is in a position where the recordingmedium can be placed or taken out, FIG. 23C shows that the disc tray isin a position between FIGS. 23A and 23B, FIG. 23D shows that therecording unit is housed in the housing part, FIG. 23E illustrates thatthe disc tray is in a position between FIGS. 23D and 23F, and FIG. 23Fillustrates that the disc tray is in the position where the recordingmedium is loaded into a recording and/or reproducing unit.

BEST MODE FOR CARRYING OUT THE INVENTION

[0042] An embodiment of the invention will be described hereinbelow withreference to the drawings. FIGS. 2 to 23 show the embodiment of theinvention. The invention is applied to a disc recording/reproducingapparatus for performing both recording and reproducing as an embodimentof an apparatus for recording and/or reproducing a disc-shaped recordingmedium, which records (writes) and/or reproduces (reads) information byusing, as a disc-shaped recording medium, an optical disc such as a CDor CD-R (rewritable) or an optical disc such as a magneto optic disc.

[0043] As shown in FIGS. 2 to 4, a disc recording/reproducing apparatus10 according to the embodiment of the invention comprises a chassis 11as a casing whose top face is open. In the chassis 11, there areprovided a tray stocker 12 as a housing member capable of stocking fiverecordable/reproducible optical discs D as an example of disc-shaperecording media at once; a disc rotating device 13 for chucking theoptical disc D supplied from the tray stocker 12 and rotating theoptical disc D at predetermined speed (for example, constant linearvelocity); an optical pickup device 14 for writing (recording) and/orreading (reproducing) an information signal to/from the optical disc Drotated at predetermined speed; a controller for controlling theoperations of the devices; and other devices.

[0044] As shown in FIG. 3, the chassis 11 is a rectangular casing withan open top face and comprises a bottom plate 11 a having an almostrectangle, a front plate 11 b extended from the front part of the bottomplate 11 a, right and left side plates 11 c and 11 d continued from bothsides of the bottom plate 11 a, and a rear plate 11 e continued from therear part of the bottom plate 11 a. As illustrated in FIG. 4, on thefront plate 11 b of the chassis 11, a tray insertion/ejection port 15 asan elongated opening which extends in the lateral direction is formed bysetting the height of the front plate 11 b so as to be lower than theside plates 11 c and 11 d and the like.

[0045] As shown in FIGS. 2 to 4, one of the side plates, 11 c, of thechassis 11 is provided with a shelf 11 f on which a side mount base 25is attached. On the other side plate 11 d of the chassis 11, as shown inFIGS. 3 and 4, two vertical grooves 26 and 26 extend vertically with apredetermined gap in the longitudinal direction.

[0046] The side mount base 25 has a fixed plate 25 a extending in thelongitudinal direction and a side wall 25 b continued on one side in thewidth direction of the fixed plate 25 a. The side wall 25 b of the sidemount base 25 is developed in the direction which perpendicularlycrosses the plane direction of the fixed plate 25 a. The side mount base25 is detachably fixed to the chassis 11 by a plurality of fixing screws65.

[0047] In the side wall 25 b of the side mount base 25, two verticalgrooves (not shown) are provided with a predetermined gap in thelongitudinal direction. The two vertical grooves are formed in positionsopposite to the two vertical grooves 26 and 26 formed in the other sideplate 11 d in a state where the side mount base 25 is fixed to the sideplate 11 d. The two vertical grooves have the size similar to that ofthe vertical grooves 26, 26. By being guided along the four verticalgrooves, the tray stocker 12 is moved up and down as will be describedhereinlater. The side mount base 25 is provided with four supportingshafts 69 a to 69 d and a driving motor 61 which will be describedhereinlater.

[0048] On both sides of the tray insertion/ejection port 15, a pair oftray guides 16, 16 protruding from the front plate 11 b and extendingrearward, that is, to the inside are provided. The pair of tray guides16, 16 support both sides in the direction crossing the carryingdirection of the disc tray 17 as a placement member from below. The pairof tray guides 16, 16 are provided with guide rails 16 a, 16 a extendingin the tray carrying direction as the longitudinal direction of thechassis 11 so as to protrude upward.

[0049] As shown in FIGS. 2, 6, and so on, on the front side of thechassis 11, a front mount base 18 is fixedly mounted by fixing screws 19as fixing means. The front mount base 18 is a block member attachedacross the chassis 11. Under both ends in the longitudinal direction ofthe front mount base 18, a pair of tray pressers 18 a and 18 b disposedso as to face the pair of tray guides 16, 16 in the vertical directionare provided.

[0050] When the disc tray 17 is ejected, both sides of the disc tray 17are supported so as to be sandwiched by the tray guides 16, 16 and thetray pressers 18 a, 18 b which are paired with each other in thevertical direction. Consequently, as shown in FIGS. 9 and 12, the frontpart of the disc tray 17 is projected from the front plate 11 b and thedisc tray 17 is held in an overhung state in the ejected position inwhich the optical disc D can be placed or taken out.

[0051] To the tray presser 18 a of the front mount base 18, as shown inFIGS. 6, 11, and so on, a front detection arm 20 and a rear detectionarm 21 for detecting the disc tray 17 are attached so as to be swingablein the vertical direction. Each of the detection arms 20 and 21 has aninput part projecting on the path of the disc tray 17. Detectionswitches 22 a and 22 b are disposed above, that is on the side oppositeto the detection arms 20 and 21, respectively. The detection arm 20 or21 is pushed up by the disc tray 17 to turn on (or off) thecorresponding detection switch 22 a or 22 b, thereby enabling thepassage of the disc tray 17 in the position where the switch is attachedto be detected.

[0052] Further, as shown in FIG. 4, a front feed gear 23 is rotatablyattached to one of the tray guides 16. A rack which will be describedhereinlater formed in the disc tray 17 comes into engagement with thefront feed gear 23 at the time of ejection. By the rotational force ofthe front feed gear 23, the disc tray 17 is moved forward or rearwardaccording to the rotation direction.

[0053] As shown in FIGS. 2, 5, and so on, on the front face of the frontplate 11 b and on the inside of the pair of tray guides 16, 16, a door27 for closing the tray insertion/ejection port 15 is attached. The door27 is a plate member which is elongated in the lateral direction andshafts 27 a, 27 a projecting outward in the longitudinal direction areprovided under both ends. On the inside of the pair of tray guides 16,16, a pair of bearings 28 a and 28 b are provided to swingably supportthe shafts 27 a, 27 a. Both ends of the door 27 are supported by thefront plate 11 b by the bearings 28 a and 28 b so as to be swingable.

[0054] A coil spring 29 is attached to one of the shafts, 27 a, of thedoor 27. By the spring force of the coil spring 29, the door 27 isenergized and the tray insertion/ejection port 15 is closed by the door27. The disc tray 17 inserted/ejected to/ from the trayinsertion/ejection port 15 is a plate member larger than the opticaldisc D used as shown in FIG. 13.

[0055] In the central part of the disc tray 17, for example, a discplacement part 30 having a recess 30 a of a large diameter on which theoptical disc D having a diameter of 12 cm is placed and a recess 30 b ofa small diameter on which the optical disc D having a diameter of 8 cmis placed. In the center of the front part of the disc tray 17, acentral protruding part 17 a of a trapezoid shape is created by formingrectangular notches 31 a and 31 b on both sides. On the side opposite tothe central protruding part 17 a of the disc tray 17, a pair of parts 17b and 17 c to be supported, which project in parallel to each other tothe outside with resect to the disc placement part 30 as a center areprovided.

[0056] The disc tray 17 has an open hole 34 opened in a slit shape fromthe central part to the rear part of the disc placement part 30. Aturntable 33 of the disc rotating device 13 and the like are inserted tothe open hole 34. In the position where the disc tray 17 is housed inthe tray stocker 12, the open hole 34 also serves as a path of lightfrom a photodetector 48 for detecting whether the optical disc D isplaced in the disc placement part 30 or not.

[0057] A clearance 35 is formed in a part which is surrounded by therear part of the disc placement part 30 of the disc tray 17 and the pairof parts 17 b, 17 c to be supported extended on both ends. By theclearance 35, contact with a cam member, a gear, and the like which willbe described hereinlater can be avoided. Further, when two disc trays 17are arranged in the vertical direction, the central protruding part 17 aof the other disc tray 17 can enter the clearance 35, thereby enablingthe length in the vertical direction to be reduced.

[0058] Specifically, as shown in FIG. 14, the central protruding part 17a of one disc tray 17 can enter the clearance 35 of the other disc tray17. By arranging the two disc trays 17 in the vertical direction in sucha manner, the length in the vertical direction of the whole can beshortened only by a distance S as compared with a case where twoconventional disc trays 37 each having no notches on both sides of thefront part are arranged only by the distance S. Consequently, thedistance between a stock position where the disc tray 17 is stocked inthe tray stocker 12 and a play position where the optical disc D placedon the disc tray 17 is loaded to the optical pickup device 14 isshortened to thereby shorten the length in the depth direction of theapparatus. Thus, the size of the whole apparatus can be reduced.

[0059] As shown in FIG. 13, a detection hole 36 for passing light usedfor disc detection by the photodetector 48 is opened in the frontportion of the disc placement part 30 of the disc tray 17, which is thepart where the detection light of the photodetector 48 passes, that is,on the path in the carrying direction T of the disc tray 17 passing thecenter point C or around it of the disc placement part 30. The detectionhole 36 is used to detect whether the optical disc D is placed on thedisc placement part 30 or not when the disc tray 17 is moved between thestock position and the play position.

[0060] In the embodiment, the detection hole 36 is provided in therecess 30 b of a small diameter of the disc placement part 30. Thedetection hole 36 can be also formed in the recess 30 a of a largediameter as long as it is on the path of the detection light. The sizeof the detection hole 36 is properly set in consideration of the movingspeed of the disc tray 17, the light detection sensitivity of thephotodetector 48, and the like.

[0061] On both edges in the direction which perpendicularly crosses thecarrying direction T of the disc tray 17, guide grooves 38 a and 38 bwhich open on the under face side and extend straight in thelongitudinal direction are formed. The guide grooves 38 a and 38 b havethe role of regulating the lateral movement of the disc tray 17 tolinearly insert/eject the disc tray 17 to/from the trayinsertion/ejection port 15. At the time of ejection, the guide rails 16a, 16 a of the pair of tray guides 16, 16 of the chassis 11 are slidablefit in the guide grooves 38 a, 38 b.

[0062] Further, on one of the edges of the disc tray 17, a rack 39formed from the front end to the rear end of the part 17 b to besupported is provided. Near the rear end of the part 17 b to besupported, a V-shaped notch 41 is formed as a positioning part used forpositioning by a slider 40 as a switching slider. Further, a lock hole42 as a retained part for locking the disc tray 17 to prevent movementof the disc tray 17 is opened near the part 17 b to be supported.

[0063] The five disc trays 17 each having the above construction arestacked so that information recording planes as main planes of theoptical discs D placed on the disc placement parts 30 are almost inparallel to each other, and stocked in the tray stocker 12. As shown inFIG. 15, the tray stocker 12 has a base plate 12 a formed slightly widerthan the disc tray 17 and right and left side plates 12 b and 12 cattached upright on both sides in the width direction of the base plate12 a. As shown in FIG. 3, the right and left side plates 12 b and 12 care fixed by fixing means such as fixing screws 43 a integrally with thebase plate 12 a.

[0064] As shown in FIGS. 3 and 15, on the inside of the side plates 12 band 12 c of the tray stocker 12, five shelf pieces 12 d and 12 d areprovided at predetermined intervals in the vertical direction so as tobe in parallel with each other. The top shelf piece 12 d prevents thedisc tray 17 stocked uppermost from being come off to the above. Betweenthe neighboring shelf pieces 12 d, 12 d facing in both vertical andlateral directions and between the lowermost shelf piece and the bottom,a tray housing part is defined. Between the neighboring shelf pieces orbetween the shelf piece and the bottom, the right and left side edges ofthe disc tray 17 are placed to detachably hold the disc tray 17 in eachtray housing part.

[0065] In one of the side plates, 12 b, of the tray stocker 12, an openwindow 45 to which a central feed gear 44 as a feed gear to be engagedwith the rack 39 of the disc tray 17 is inserted is opened. The openwindow 45 has a five-layer structure and is opened for each of the fivetray housing parts. By inserting the central feed gear 44 via thecorresponding hole into the tray housing part in accordance with theelevating position of the tray stocker 12, the central feed gear 44comes into engagement with the rack 39 of the disc tray 17 held in thetray housing part.

[0066] As shown in FIGS. 3 and 5, a stopper plate 46 is attached to thefront of the tray stocker 12 by fixing means such as fixing screws 43 b.The stopper plate 46 regulates forward movement of the tray stocker 12.A top plate 47 is spanned between the right and left side plates 12 band 12 c. The top plate 47 is fastened on the top of the side plates 12b and 12 c by a plurality of fixing screws 43 c.

[0067] Further, as shown in FIG. 15, in an almost central part of thebase plate 12 a, a light passing hole 49 through which light of thephotodetector 48 passes is formed. As shown in FIG. 7, a sensor holdingpart 11 h provided on the bottom plate 11 a of the chassis 11 isinserted to the light passing hole 49. As shown in FIG. 15, two screwholes 51 are provided with a predetermined gap in the longitudinal oneach of both side faces of the base plate 12 a. Screw parts of guidepins 50 are screwed in the screw holes 51. Total four guides pins 50 areprojected two each on the right and left sides of the base plate 12 a.

[0068] The tray stocker 12 having such a construction is placed on asliding member 53 as a slider for elevating the tray stocker 12 as ahousing member. As shown in FIG. 16, the sliding member 53 has a bottomplate 53 a formed slightly wider than the tray holder 12 and right andleft side plates 53 b and 53 c extending upright from the right and leftsides of the bottom plate 53 a. In the bottom plate 53 a of the slidingmember 53, guide holes 54 and 55 for moving the sliding member 53 in theback and forth directions are opened. One of the two guide holes, 54, isformed in an almost center of the front part of the bottom plate 53 aand the other guide hole 55 is formed in a position slightly offset toone side from the guide hole 54.

[0069] In the front portions of the guide holes 54 and 55, wide mouths54 a and 55 a each for inserting the head of a member for preventing thesliding member 53 from being come off are formed. As shown in FIG. 5 andthe like, the sensor holding part 11 h provided for the bottom plate 11a of the chassis 11 is inserted to one of the guide holes, 54. A guideprojection 11 i provided for the bottom plate 11 a is similarly insertedto the other guide hole 55. While being guided by the sensor holdingpart 11 h and the guide projection 11 i, the sliding member 53 issupported by the chassis 11 so as to be slidable in the longitudinaldirection.

[0070] Further, as shown in FIG. 16, between the guide hole 55 and oneof the side plates, 53 b in the rear part of the bottom plate 11 a ofthe chassis 11, a notch 53 d extending in the longitudinal direction isformed. At one of the edges of the notch 53 d, a rack 57 having teetharranged in the longitudinal direction, which come into engagement witha drive gear 112 which will be described hereinlater is formed. A notch53 e for avoiding contact with a cam member and the like which will bedescribed hereinlater is formed between the guide hole 55 and the otherside plate 53 c.

[0071] Each of the right and left side plates 53 b and 53 c of thesliding member 53 has two cam grooves 58, 58 for elevation which areformed with a predetermined gap in the longitudinal direction. The fourcam grooves 58 for elevation are long stairlike holes having the sameshape and size. The cam grooves 58 on the right side plate 53 b andthose on the left side plate 53 c are arranged so as to face each other.The guide pins 50 fixedly screwed in the tray stocker 12 are slidablyfit in the cam grooves 58 for elevation.

[0072] Each of the guide pins 50 is a screw member having a steppedshaft part. The shaft part slides along the cam groove 58 for elevation.The guide pins 50 penetrating the vertical grooves of the side mountbase 25 are inserted in the front and rear cam grooves 58, 58 forelevation on one of the side plates, 53 b. The guide pins 50 penetratingthe vertical grooves 26, 26 formed in the other side plate 11 d of thechassis 11 are inserted to in the front and rear cam grooves 58, 58 forelevation of the other side plate 53 c.

[0073] Each cam groove 58 for elevation has five horizontal parts 58 aformed at predetermined intervals in the vertical direction and fourinclined parts 58 b communicating the neighboring upper and lowerhorizontal parts 58 a. The five horizontal parts 58 a are formed so thattheir height corresponds to the five tray housing parts of the traystocker 12. The tray insertion/ejection port 15 is formed incorrespondence with the height of the tray stocker 12.

[0074] To be specific, when the four guide pins 50 inserted to the camgrooves 58 for elevation are on the lowermost horizontal part 58 a, theuppermost tray housing part of the tray stocker 12 and the trayinsertion/ejection port 15 are set to have almost the same height. Whenthe four guide pins 50 move to the fifth horizontal part 58 a which isthe uppermost, the tray stocker 12 is lifted only by a predeterminedamount and the first tray housing part as the lowermost part coincideswith the tray insertion/ejection port 15.

[0075] Such an operation of elevating the tray stocker 12 is realized bya synergistic effect among the two vertical grooves 26, 26 formed in oneof the side plates, 11 d, of the chassis 11, the two vertical groovesformed in the side mount base 25, and the four cam grooves 58, 58 forelevation formed in the sliding member 53. Specifically, the traystocker 12 is supported by the four vertical grooves so as to be movableonly in the vertical direction with respect to the chassis 1 and thesliding member 53 is supported so as to be movable only in thelongitudinal direction with respect to the chassis 11. By moving thesliding member 53 in the longitudinal direction, the tray stocker 12 ismoved vertically by the operation of the stocker elevating mechanismcomprising the vertical grooves 26, 26, guide pins 50, 50, and camgrooves 58, 58 for elevation.

[0076] The side mount base 25 for inserting/ejecting the disc tray 17housed in the tray stocker 12 to/from the tray insertion/ejection port15 is provided with a tray carrying mechanism 60 as a carrying mechanismfor moving the disc tray 17. The tray carrying mechanism 60 moves thedisc tray 17 among an ejection position where the optical disc D can beloaded or ejected to/from the disc tray 17, a stock position where thedisc tray 17 is housed in the tray stocker 12, and a play position wherethe optical disc D is loaded in the recording and/or reproducing unit.

[0077] The tray carrying mechanism 60 as a component of a disc traycarrying system has a construction as illustrated in FIGS. 2, 5, and soon. Specifically, the tray carrying mechanism 60 comprises a drivingmotor 61 as a drive source, a rubber belt type speed reducing mechanism62 for increasing a transmission torque by reducing the rotational speedof the driving motor 61, and three feed gears 23, 44, and 63 rotated bythe torque transmitted from the rubber belt speed reducing mechanism 62.

[0078] As shown in FIG. 2 and so on, the driving motor 61 of the traycarrying mechanism 60 is fixed to the side mount base 25. The rotaryshaft 61 a of the driving motor 61 penetrates the fixed plate 25 a andis projected upward. A driving pulley 67 is attached to the rotary shaft61 a. As shown in FIG. 18, the driving pulley 67 has three beltretaining parts provided with predetermined intervals in the axialdirection. Endless rubber belts 68 a, 68 b, and 68 c as powertransmitting media are run over the belt retaining parts of the drivingpulley 67.

[0079] The first rubber belt 68 a run over the central belt retainingpart of the driving pulley 67 extends to the front side of the chassis11 and runs over a front driven pulley 70 a. The second rubber belt 68 brun over the lower belt retaining part of the driving pulley 67 extendsto the rear side of the chassis 11 and runs over a central driven pulley72 a. Further, the third rubber belt 68 c run over the upper beltretaining part of the driving pulley 67 extends to the rear side of thechassis 11 and runs over a rear driven pulley 75 a.

[0080] As shown in FIGS. 5, 9, and 10, the front driven pulley 70 a isrotatably supported by the supporting shaft 69 a upright in the frontpart of the side mount base 25. The front driven pulley 70 a isintegrally provided with a front output gear 70 b which engages with alarge diameter part 71 a of the front intermediate gear 71. The frontintermediate gear 71 has a small diameter part 71 b provided integrallywith the large diameter part 71 a and is rotatably supported by thesupporting shaft 69 b upright on the front side of the supporting shaft69 a. The above-mentioned front feed gear 23 is in engagement with thesmall diameter part 71 b of the front intermediate gear 71.

[0081] The central driven pulley 72 a is rotatably supported by thesupporting shaft 69 c upright in the intermediate part of the side mountbase 25. A swing arm 23 as an arm part rotatably similarly supported bythe supporting shaft 69 c is disposed below a central driven pulley 72a. On the swing arm 73, a central output gear 72 b provided integrallywith the central driven pulley 72 a is placed.

[0082] A large diameter part 74 a of a central intermediate gear 74engages with the central output gear 72 b. The large diameter part 74 ais integrally provided with a small diameter part 74 b. Theabove-mentioned central feed gear 44 engages with the small diameterpart 74 b of the central intermediate gear 74. The central feed gear 44and the central intermediate gear 74 are rotatably supported by shafts73 c and 73 d formed upright in one of the arm members, 73 a, of theswing arm 73 as shown in FIGS. 17 and 18. The central feed gear 44 andthe central intermediate gear 74 therefore rotate around the centraloutput gear 72 b by the swinging operation of the swing arm 73.

[0083] When the swing arm 73 swings clockwise in FIG. 17, the centralfeed gear 44 enters the tray housing part from the open window 45 formedin the tray stocker 12. As a result, when the disc tray 17 is housed inthe corresponding tray housing part, the central feed gear 44 comes intoengagement with the rack 39 of the disc tray 17. The other arm member 73b of the swing arm 73 is provided with an operation pin 73 e protrudingdownward.

[0084] The rear driven pulley 75 a is rotatably supported by thesupporting shaft 69 c provided upright on the rear side of the sidemount base 25. The rear driven pulley 75 a is integrally provided with arear output gear 75 b. A large diameter part 76 a of a rear intermediategear 76 engages with the rear output gear 75 b. The large diameter part76 a of the rear intermediate gear 76 is integrally provided with asmall diameter part 76 b.

[0085] The rear intermediate gear 76 is rotatably supported by asupporting shaft 77 a provided upright in the chassis 11. Below the rearintermediate gear 76, a stepped switching lever 78 similarly rotatablysupported by the supporting shaft 77 a is disposed. On the steppedswitching lever 78, the small diameter part 76 b of the rearintermediate gear 76 is placed.

[0086] The stepped switching lever 78 has, as shown in FIG. 22, acylindrical shaft 78 a and two arms 78 b and 78 c projected from thecylindrical shaft 78 a. The first arm 78 b is provided with an operationpin 78 d projected upward and the second arm 78 c is provided with aninclined face 78 e which is radially inclined. An upper face 78 f and alower face 78 g are set on both sides of the inclination direction ofthe inclined face 78 e, thereby forming a step of a predeterminedheight. In the inclined face 78 e, a long hole 79 extending in theinclination direction between the upper face 78 f and the lower face 78g is formed.

[0087] The long hole 79 of the stepped switching lever 78 has a circularshape around the axis of the cylindrical part 78 a as a center. As shownin FIG. 21, a supporting shaft 77 b provided upright in the chassis 11is slidably inserted to the long hole 79. An elevating gear 80 as amoving gear is rotatably supported by the supporting shaft 77 b. Theelevating gear 80 is energized toward the second arm 78 c by the springforce of a coil spring 81 a. The elevating gear 80 has a large diameterpart 80 a to be engaged with the small diameter part 76 b of the rearintermediate gear 76 and a small diameter part 80 b integrally providedunder the large diameter part 80 a.

[0088] The elevating gear 80 moves up or down along the inclined face 78e against the energization force of the coil spring 81 a by the swing ofthe stepped switching lever 78. As a result, the elevating gear 80 canbe moved onto the upper face 78 f (first position) and the lower face 78g (second position). Before and after the elevating operation, as shownin FIGS. 18 and 21, the large diameter part 80 a of the elevating gear80 always engages with the small diameter part 76 b of the rearintermediate gear 76.

[0089] As illustrated in FIG. 18, a movable gear 82 detachably engageswith the large diameter part 80 a of the elevating gear 80. The movablegear 82 is rotatably supported by a supporting shaft 77 c providedupright on the chassis 11 and is energized toward the bottom plate 11 aof the chassis 11 by the spring force of a coil spring 81 b. Below themovable gear 82, an operation arm 83 a provided for a swing frame 83which will be described hereinlater is disposed so as to face themovable gear 82. The operation arm 83 a swings vertically, therebymoving the movable gear 82 up or down against the energization force ofthe coil spring 81 b.

[0090] Before and after the elevating operation, when the elevating gear80 moves upward and is in the first position, the movable gear 82engages with the large diameter part 80 a. When the elevating gear 80moves downward and is in the second position, the engagement with thelarge diameter part 80 a is cancelled. The movable gear 82 engages witha rear feed gear 63 as another feed gear. The rear feed gear 63 isrotatably supported by the side mount base 25 and thickly formed so asto always engage with the movable gear 82 before and after the elevatingoperation of the movable gear 82. The other ends of the two coil springs81 s and 81 b are connected to a spring bracket 25 a provided for theside mount base 25.

[0091] In FIGS. 5, 9, and 10, therefore, when the driving motor 61rotates clockwise as shown by the arrow of a solid line, the threedriven pulleys 70 a, 72 a, and 75 a are rotated clockwise by the drivingpulley 67 via the three rubber belts 68 a to 68 c. Consequently, in thefront carrying part to which the torque is transmitted from the frontdriven pulley 70 a, the front feed gear 23 is rotated clockwise via theoutput gear 70 b and an intermediate gear 71. In the central carryingpart where the torque is transmitted from the central driven pulley 72a, the central feed gear 44 is rotated clockwise via the output gear 72b and the intermediate gear 74. Further, in the rear carrying part wherethe torque is transmitted from the rear driven pulley 75 a, the rearfeed gear 63 is similarly rotated clockwise via the output gear 75 b,intermediate gear 76, elevating gear 80 (the large diameter part 80 aand the small diameter part 80 b), and movable gear 82.

[0092] At this time, since the front feed gear 23 in the front carryingpart and the central feed gear 44 in the central carrying part aredirectly connected to the output gears 70 b and 72 b, respectively, bothof the feed gears 23 and 44 are always rotated. On the other hand, inthe rear carrying part, since the elevating gear 80 and the movable gear82 are constructed to be disengageable, the rear feed gear 63 is eitherrotated or stopped according to the engagement/disengagement.

[0093] Since the front and rear feed gears 23 and 63 are supported inthe predetermined positions in the chassis 1 and positioned on the pathof the rack 39 formed in the disc tray 17, when the disc tray 17 ismoved to the position, the front and rear feed gears 23 and 63 alwayscome into engagement with the rack 39. On the other hand, since thecentral feed gear 44 is supported by the swing arm 73, the central feedgear 44 projects onto the path of the rack 39 in accordance with theswing operation of the swing arm 73. Only at that time, the central feedgear 44 comes into engagement with the rack 39.

[0094] On the rear side of the tray stocker 12 in which a plurality ofdisc trays 17 inserted/ejected by the tray carrying mechanism 60 havingsuch a construction are housed, the swing frame 83 swingably supportedby the chassis 11 is disposed.

[0095] As shown in FIGS. 2 to 5, the swing frame 83 is a frame memberhaving an almost square shape. As shown in FIGS. 6, 8, and 11, theoperation arm 83 a is provided so as to project from the front lowerpart of one of the side faces of the swing frame 83. A rotary shaft 83 bas a rotation center with respect to the chassis 11 is provided in therear upper part of both sides of the swing frame 83. The rotary shaft 83b is rotatably supported by a bearing supporting part provided for thechassis 11. The swing frame 83 is swingable so that its front side islower with respect to the chassis 11.

[0096] Further, as shown in FIG. 4, on the swing frame 83, a lock pin117 as a fitting projection protruding upward is provided. The lock pin117 is fit in the lock hole 42 as a part to be fitted in the disc tray17 at the time of chucking, thereby locking the disc tray 17 andpreventing the movement of the disc tray 17. The fitting part and thepart to be fitted can be provided in a manner opposite to the embodimentthat the lock pin is provided for the disc tray 17 and the lock hole isformed in the swing frame 83.

[0097] In order to assure the inclining operation of the swing frame 83,as shown in FIG. 3 and the like, an open window 84 slightly larger thanthe swing frame 83 is opened in the bottom plate 11 a of the chassis 11.Only when the front side of the swing frame 83 is inclined downward,that is, only in the state before the chucking, the front lower part ofthe swing frame 83 is projected downward from the open window 84. In theswing frame 83, a sub-chassis 86 is elastically supported via fourdamper members 85. On the sub-chassis 86, the disc rotating device 13and the optical pickup device 14 are mounted.

[0098] The damper member 85 is a hollow gourd-shaped cylindrical bodymade of a rubber-like elastic material. By elastically supporting thesub-chassis 86 by the four damper members 85, the vibration on thechassis 11 side is prevented from being transmitted to the disc rotatingdevice 13 and the like. The disc rotating device 13 has a spindle motor87 fixed to the front part of the sub-chassis 86. A turntable 33 isattached to the tip of a rotary shaft provided upright on the spindlemotor 87. The turntable 33 is set so as to be almost parallel to the topface of the sub-chassis 86. A centering guide to be fit in the centralhole (d) of the optical disc D is provided in the center of the top faceof the turntable 33.

[0099] As shown in FIG. 5 and the like, behind the spindle motor 87, theoptical pickup device 14 is guided by a guide shaft 88 a and a guideplate 88 b and supported so as to be movable in the longitudinaldirection. The guide shaft 88 a and the guide plate 88 b are fixed tothe sub-chassis 86 so as to be parallel to each other. A carriage 14 ais slidably supported by the guide shaft 88 a and the guide plate 88 band the optical pickup device 14 can be moved so as to be close to orapart from the turntable 33 via the sliding operation of the carriage14a.

[0100] On the carriage 14 a of the optical pickup device 14, an opticalhead 14 c on which an objective lens 14 b is installed so as to faceupward is mounted. A laser beam emitted from the objective lens 14 b isapplied to the information recording face of the optical disc D chuckedby the turntable 33 and the laser beam reflected by the informationrecording face enters the optical head 14 c via the objective lens 14 b.The center of each of the objective lens 14 b and the turntable 33 isset on the path of the center of the disc tray 17. The objective lens 14b is movable in the radial direction of the optical disc D in the rearpart of the optical disc D placed on the turntable 33.

[0101] As shown in FIGS. 2, 12 and so on, a disc clamper 89 forsandwiching the optical disc D with the turntable 33 so as to beintegrally rotatable is disposed above the turntable 33. The discclamper 89 is held by a rear mount base 90 with a predetermined play ineach of the vertical, lateral, and longitudinal directions, which isprovided so as to cover the swing frame 83. The rear mount base 90 isattached across the right and left side plates 11 c and 11 d in the rearpart of the chassis 11 and is fixed by a plurality of fixing screws 19a.

[0102] The disc damper 89 is attached in an almost center part of therear mount base 90. The disc damper 89 has a cylindrical shaft extendingthrough a hole formed in the rear mount base 90, a flange-shaped presserplate provided at the lower end of the cylindrical shaft, and a mountingplate detachably attached to the upper end of the cylindrical shaft. Amagnet for chucking is housed in the cylindrical shaft, so that the discdamper 89 is attracted by the turntable 33 by the attraction force ofthe magnet. Consequently, the optical disc D placed on the turntable 33is sandwiched by the disc clamper 89 and the turntable 33 and rotated inthe chucked state.

[0103] As shown in FIG. 5 and so on, on one of the sides of the rearmount base 90, a front detection arm 91 and a rear detection arm 92 fordetecting whether or not the disc tray 17 is moved to the play positionwhere the information signal is recorded and/or reproduced are attachedswingably in the vertical direction. The detection arms 91 and 92 haveinput parts 91 a and 92 a projected onto the path of the disc tray 17and the detection switches 22 c and 22 d are disposed on the sideopposite to the input parts 91 a and 92 a, respectively. By turning on(or off) the corresponding detection switch 22 c or 22 d by pushing upthe detection arm 91 or 92 by the disc tray 17, it can be detected thatthe disc tray 17 passes through the position where the switch isattached.

[0104] Further, on the inner face of one of the side plates, 11 d, ofthe chassis 11 and the inner face of the side mount base 25, rear guiderails 93 a ad 93 b for supporting the disc tray 17 from both sides,which is carried from the rear side of the tracy stocker 12 to theturntable 33 side are provided. The height of the rear guide rails 93 aand 93 b is set to be almost the same as that of the trayinsertion/ejection port 15 surrounded by the pair of tray guides 16, 16and the tray pressers 18 a and 18 b.

[0105] As shown in FIGS. 5, 6 and so on, a cam pin 94 protruding forwardis provided in the upper central part of the front face of the swingframe 83. In order to reduce the slide frictional resistance, the tip ofthe cam pin 94 is formed in a spherical shape. The cam pin 94 isslidably fit in a cam groove 96 of a cam member 95 disposed in front ofthe cam pin 94.

[0106] As shown in FIGS. 4, 19 and so on, the cam member 95 is arotating member having the cam groove 96 spirally extending on theperiphery. A cam gear 95 a is provided at the lower end of the cammember 95 and a end face cam 95 b is provided on the top face. The camgroove 96 of the cam member 95 has an inclined part 96 a inclined at apredetermined angle and an upper horizontal part 96 b and a lowerhorizontal part 96 c which are continuous on both sides of the inclinedpart 96 a.

[0107] The inclined part 96 a in the cam groove 96 is a long groovewhose right side is lower. In a higher position on the left side of theinclined part 96 a, the upper horizontal part 96 b is formed. In a lowerposition on the right side of the inclined part 96 a, the lowerhorizontal part 96 c is formed. The upper horizontal part 96 b of thecam groove 96 is set in a position as high as the swing frame 83 in ahorizontal state. As shown in FIGS. 11 and 12, when the swing frame 83is in the horizontal state, the optical disc D on the disc tray 17 islifted by the turntable 33 of the optical pickup device 14.

[0108] The swing frame 83 is moved up or down by the cam member 95. Asshown in FIGS. 6 and 8, the swing frame 83 is swung so that its frontside is lowered only by an amount corresponding to the differencebetween the upper and lower horizontal parts 96 b and 96 c. The inclinedstate where the front side of the swing frame 83 is lower corresponds tothe position where the turntable 33 is lower than the disc tray 17. Thecam member 95 for swinging the swing frame 83 is rotatably supported bythe supporting shaft 77 d in a state where the cam gear 95 a is disposedbelow. The support shaft 77 d is provided upright on the bottom plate 11a of the chassis 11 as shown in FIG. 3.

[0109] Further, as shown in FIGS. 17 and 19, an output gear 98positioning at the end of the power transmitting path in a cam drivingmechanism 97 of the chucking operation system meshes with the cam gear95 a of the cam member 95. The output gear 98 meshes with a smalldiameter part 99 a of an intermediate gear 99. The small diameter part99 a is integrally provided with a large diameter part 99 b. A drivinggear 100 a engages with the large diameter part 99 b of the intermediategear 99.

[0110] The driving gear 100 a is integrally provided with a drivenpulley 100 b. The endless rubber belt 68 d runs over the driven pulley100 b, extends rearward and runs over a driving pulley 101 a. Thedriving pulley 101 a is fixed to the rotary shaft of a cam driving motor101. The cam driving motor 101 is fixed on the inside of the side plate11 d of the chassis 11. The driving gear 100 a, intermediate gear 99,and output gear 98 are rotatably supported by the supporting shaftsprovided upright on the bottom plate 11 a.

[0111] As shown in FIG. 4 and so on, the end face cam 95 b provided onthe top face of the cam member 95 is an annular groove deviated to oneside with respect to the rotation center of the cam member 95 as acenter. A stroke of a predetermined distance is set according to adisplacement amount in the radial direction of the end face cam 95 b. Asshown in FIG. 20, a projection 40 a from the back face of the slider 40is slidably fit in the end face cam 95 b.

[0112] The slider 40 is a plate member which is long in the lateraldirection as shown in FIGS. 3 to 5. Two long holes 40 b and 40 cextending in the lateral direction with a predetermined interval in thelongitudinal direction are opened in the slider 40. One of the longholes, 40 b, of the slider 40 faces the top of the supporting shaft 77 dfor supporting the cam member 95. The slider 40 is prevented from beingcome off by an attaching screw 102 a screwed in the top of thesupporting shaft 77 d while being guided in the lateral direction. Theother long hole 40 c of the slider 40 extends higher than the supportingshaft 77 e provided upright on the chassis 11. Similarly, the slider 40is prevented from being come off by an attaching screw 102 b screwed inthe top of the supporting shaft 77 e while being guided in the lateraldirection.

[0113] An arm member 40 d is provided on the side mount base 25 side ofthe slider 40. At the front end of the arm member 40 d, two operationloops 103 a and 103 b and a positioning piece 104 are provided. As shownin FIG. 17, an operation pin 73 e of the swing arm 73 is looselyinserted in one of the operation loops, 103 a, of the slider 40 and theoperation pin 78 d of the stepped switching lever 78 is loosely insertedto the other operation loop 103 b. The positioning piece 104 of theslider 40 is used to position the disc tray 17 in the stock position. Byfitting the positioning piece 104 to the V-shaped notch 41 of the disctray 17, the disc tray 17 is positioned in the stock position so thatthe movement in the back and forth direction is regulated.

[0114] As illustrated in FIGS. 3 to 5, an elevating shutter 105 issupported on the front face side of the slider 40 so as to be movable inthe vertical direction. The elevating shutter 105 is used to prevent theoptical disc D placed on the disc placement part 30 of the disc tray 17from being moved to the disc loading side by a disturbance such asvibration. Usually, the upper part of the elevating shutter 105 isprotruded from the upper end face of the cam member 95. When the disctray 17 is conveyed to the disc loading side, the elevating shutter 105is lowered only by a predetermined amount so as to make the disc tray 17pass.

[0115] The elevating shutter 105 has a pair of right and left inclinedguide holes 106, 106. In the pair of guide holes 106, 106, a pair ofguide pins 107, 107 provided for the slider 40 are slidably fit. Asshown in FIG. 3, a spring 108 is provided across the slider 40 and theelevating shutter 105. By the spring force of the spring 108, theelevating shutter 105 is always energized toward the side mount base 25.

[0116] In order to regulate the lateral movement of the elevatingshutter 105, a stopper 109 is provided upright on the bottom plate 11 aof the chassis 11. By the stopper 109, the lateral movement of theelevating shutter 105 is regulated. Further, by guiding the pair ofguide pins 107, 107 along the pair of guide holes 106, 106, the wholeelevating shutter 105 is pressed down and moves downward almost inparallel.

[0117] A Geneva pin gear 110 constructing one of Geneva gears isrotatably supported by the supporting shaft 77 e for supporting the sidemount base 25 side of the slider 40. As shown in FIGS. 20 and 21, theGeneva pin gear 110 has a cam protruding part 110 a protruded in a fanshape, a cam pin 110 b provided on the outside in the radial directionof the cam protruding part 110 a, and a switch operation part 110 cformed by expanding the lower part of the cam protruding part 100 a.

[0118] Near the Geneva pin gear 110, a Geneva groove gear 111 isslidably provided. A Geneva gear is constructed by the pair of gears 110and 111. As shown in FIGS. 17 and 20, the Geneva groove gear 111 has acam groove 111 a formed in a cross shape to which the cam pin 110 b ofthe Geneva gear 110 is slidably fit, a stopper curve 111 b for checkingthe transmission of the rotational force, which is slidably in contactwith the periphery of the cam protruding part 110 a of the Geneva pingear, and a gear part 111 c integrally formed with the cam groove 111 aand the stopper curve 111 b.

[0119] A large diameter part 112 a of the drive gear 112 meshes with thegear part 111 c of the Geneva groove gear 111. The large diameter part112 a is integrally provided with a small diameter part 112 b. The smalldiameter part 112 b is in engagement with the rack 57 of theabove-mentioned sliding member 53. As shown in FIG. 17, the Genevagroove gear 111 and the drive gear 112 are rotatably supported by thesupporting shafts 77 g and 77 h provided upright on the chassis 11,respectively.

[0120] Further, as shown in FIG. 20, a coil spring 113 is loosely fit inthe center part of the Geneva pin gear 110 and one end of the coilspring 113 is seated on a sleeve 114. The sleeve 114 is slidably fit inthe central cylindrical shaft of the Geneva pin gear 110. The sleeve 114is pressed against the under face of the slider 40. By making the campin 110 b escape from the cam groove 111 a against the energizing forceof the coil spring 113, it prevents occurrence of a failure such asdamage due to application of an excess load between the Geneva pin gear110 and the Geneva groove gear 111.

[0121] As illustrated in FIG. 2, a central mount base 115 is mounted bya plurality of fixing screws 19 b between the front mount base 18 andthe rear mount base 90. A photoreceiver 48 b is attached to the centralmount base 115 via a mounting bracket 116. A light emitting device 48 ais attached to the sensor holding part 11 h provided for the bottomplate 11 a of the chassis 11 so as to face the photoreceiver 48 b. Thephotodetector 48 is constructed by the light emitting device 48 a andthe photoreceiver 48 b.

[0122] Light (detection light) emitted from the light emitting device 48a and received by the photoreceiver 48 b is set so as to pass throughthe central hole (d) of the optical disc D placed on the disc tray 17housed in the tray housing part of the tray stocker 12. When the disctray 17 moves from the stock position to the play position, thedetection hole 36 of the disc tray 17 passes across the detection lightof the photodetector 48.

[0123] As shown in FIGS. 23A to 23F, when the disc tray 17 is moved fromthe ejection position to the stock position, the detection light of thephotodetector 48 enters the open hole 34 of the disc tray 17. At thistime, when the optical disc D is placed on the disc placement part 30 ofthe disc tray 17, the open hole 34 is closed by the informationrecording face of the optical disc D. As a result, the detection lightemitted from the light emitting device 48 a is interrupted by theinformation recording face of the optical disc D and cannot be receivedby the photoreceiver 48 b. Consequently, it can be detected that theoptical disc D is placed on the disc placement part 30.

[0124] On the other hand, when the optical disc D is not place on thedisc placement part 30, the state where the open hole 34 is open ismaintained. As a result, the detection light emitted from the lightemitting device 48 a is detected by the photoreceiver 48 b.Consequently, it can be detected that no optical disc D is placed on thedisc placement part 30. The presence or absence of the optical disc D isdetected when the disc tray 17 moves between the ejection position andthe stock position (both at the tray insertion time and the trayejection time).

[0125] Specifically, also when the disc tray 17 is moved between thestock position and the play position, the presence/absence of theoptical disc D is detected. When the optical disc D is placed on thedisc placement part 30, the detection hole 36 formed in the front partof the disc placement part 30 is closed by the optical disc D. As aresult, the detection light from the photodetector 48 is interrupted inthe front part of the disc placement part 30 and the photoreceiver 48 bcannot receive the detection light. Thus, it can be detected that theoptical disc D is placed on the disc placement part 30.

[0126] On the other hand, when no optical disc D is placed in the discplacement part 30, the state where the detection hole 36 formed in thefront part of the disc placement part 30 is opened is maintained. As aresult, when the disc tray 17 is moved to a position where the detectionhole 36 is overlapped with the detection light, the detection lightemitted from the light emitting device 48 a passes through the detectionhole 36 and is received by the photoreceiver 48 b. It can be thereforedetected that the optical disc D is not placed on the disc placementpart 30. The presence or absence of the optical disc D is detected whenthe disc tray 17 is moved between the stock position and the playposition (both at the tray set time and the tray reset time).

[0127] A stocker elevating mechanism for moving the tray stocker 12 upand down in the direction almost parallel to the stacking direction ofthe disc trays 17 is constructed by the above-described vertical groove26, guide pin 50, sliding member 53, and cam groove 58 for elevation. Aswitching mechanism is constructed by the slider 40, rear intermediategear 76, stepped switching lever 78, and elevating gear 80. By theswitching mechanism, the driving force of the driving motor 61 as adriving source is selectively supplied to the tray carrying mechanism 60and the stocker elevating mechanism.

[0128] For example, the disc recording and/or reproducing apparatus 10having such a configuration is used as follows, thereby enabling what iscalled an exchanging function to be executed. According to theexchanging function, the loading and ejecting work of the optical disc Dto/from the five disc trays 17, an operation of selecting and taking adesired one of five optical discs D placed on the disc placement parts30 of the five disc trays 17 stacked in five layers and recording orreproducing of an information signal such as music play, and a work ofexchanging the optical disc D placed on the disc placement part 30 ofthe other disc tray 17 during the recording or reproduction areperformed.

[0129] FIGS. 5 to 7 show the state where the disc trays 17 are housed,as an initial state of the disc recording and/or reproducing apparatus10. In the tray housing state, the swing frame 83 is in a state whereits front side is lower. The turntable 33 of the disc rotating device 13held by the swing frame 83 is in a lowered position. At this time,between the turntable 33 and the disc clamper 89 supported by the rearmount base 90, an appropriate gap so that one disc tray 17 can enter isset.

[0130] The tray stocker 12 for holding five disc trays 17 is positionedin the lowermost end in the stock position where the disc tray 17 ishoused. As shown in FIG. 23A, the uppermost tray housing part of thetray stocker 12 faces the tray insertion/ejection port 15.

[0131] Since the projection 40 a fit in the end face cam 95 b of the cammember 95 is positioned on the outside of the front face cam 95 b, theslider 40 is in a state where it is moved to the side mount base 25side. As shown in FIG. 17, both of the operation pins 73 e and 78 dinserted to the two operation loops 103 a and 103 b of the slider 40 aretherefore positioned displaced to the outside. The central feed gear 44positioning at the other end of the operation pin 73 e enters the trayhousing part from the open window 45 of the tray stocker 12 and mesheswith the rack 39 of the disc tray 17 held in the tray housing part.

[0132] In this state, the power source switch is turned on to supplypower to an electric system. After that, a tray operation switch in agroup of operation switches attached to a front panel (not shown)disposed on the front face or the like of the chassis 11 is operated tomake a desired disc tray 17 move forward and protruded forward from thetray insertion/ejection port 15. At this time, in the case of allowingthe fifth disc tray 17 which is the highest stage to protrude, theprotruding operation can be executed from the initial state. In the caseof allowing the fourth or lower disc tray 17 to protrude, the elevatingoperation of the stocker elevating mechanism which will be describedhereinlater is necessary before the protruding operation of the disctray 17.

[0133] First, when the tray operation switch is turned on, the drivingmotor 61 of the tray carrying mechanism 60 is driven by the function ofa controller (not shown). As shown in FIGS. 5, 9 and 10, the rotationalforce of the driving motor 61 is transmitted from the driving pulley 67to the three driven pulleys 70 a, 72 a, and 75 a in the front, central,and rear carrying parts via the three rubber belts 68 a to 68 c. As aresult, the feed gears 23 and 44 are rotated via the output gears 70 band 72 b and the intermediate gears 71 and 74 in the front and centralcarrying parts. In the rear carrying part, the feed gear 63 is rotatedvia the output gear 75 b, intermediate gear 76, elevating gear 80, andmovable gear 82.

[0134] By the rotational force of the central feed gear 44 engaged withthe rack 39 of the disc tray 17, the disc tray 17 is moved forward. Whenthe disc tray 17 is moved forward a little, the front end of the rack 39comes into engagement with the front feed gear 23, so that by therotational force of the gears 23 and 44, the disc tray 17 is movedfurther. The tip of the disc tray 17 comes into contact with the door 27and the door 27 is tilted forward, thereby exposing the trayinsertion/ejection port 15.

[0135] After that, the central feed gear 44 is apart from the rack 39.By the rotational force of the front feed gear 23, as shown in FIG. 9,the disc tray 17 is moved forward. When the disc tray 17 is protruded toa predetermined position (ejection position), the disc tray 17 in theejection position is detected by the front and rear detection arms 20and 21 and the detection switches 22 a and 22 b attached to the frontmount base 18 and the driving motor 61 is stopped on the basis of thedetection signal.

[0136] In the ejection position, almost the whole disc placement part 30of the disc tray 17 is ejected from the tray insertion/ejection port 15.Consequently, an optical disc having a diameter of 8 cm can be easilyplaced in the recess 30 b of a small diameter of the disc placement part30 or an optical disc having a diameter of 12 cm can be smoothly placedin the recess 30 a of a large diameter. The disc tray 17 is held so thatthe parts 17 b, 17 c to be supported are sandwiched by the pair of trayguides 16, 16 of the chassis 11 and the pair of tray pressers 18 a and18 b of the front mount base 18. While making the disc tray 17 projectforward as much as possible, the disc tray 17 can be firmly supported byholding the parts 17 b, 17 c to be supported on one side of the disctray 17.

[0137] Since the sufficiently large ejection amount of the disc tray 17can be assured, the optical disc D can be easily loaded or ejectedto/from the disc placement part 30. Moreover, the guide rails 16 a, 16 aof the pair of tray guides 16, 16 fit in the guide grooves 38 a, 38 bprovided on both sides of the disc tray 17 and the disc tray 17 isguided along the guide rails 16 a, 16 a. The disc tray 17 can betherefore moved straight forward and smoothly.

[0138] After the desired optical disc D is placed on the disc placementpart 30 of the disc tray 17, the front end of the disc tray 17 islightly pushed or the tray operation switch is operated. By theoperation, the driving motor 61 is rotated reversely and the rotationalforce of the driving motor 61 is transmitted from the front feed gear 23to the rack 39. The disc tray 17 is pulled into the chassis 11 from thetray insertion/ejection port 15, passes through the position (stockposition) where the optical disc D is housed in the tray housing part ofthe tray stocker 12, and is carried to the position (play position)where the optical disc D is loaded to the turntable 33 of the discrotating device 13.

[0139] At this time, in the case where the optical disc D having adiameter of 12 cm is placed in the large diameter recess 30 a of thedisc placement part 30 of the disc tray 17 or the optical disc D havinga diameter of 8 cm is placed in the small diameter recess 30 b, when thedisc tray 17 is moved from the ejection position to the stock position,the presence or absence of the optical disc D is detected by thephotodetector 48 (FIGS. 23B to 23D).

[0140] Specifically, the light emitting device 48 a and thephotoreceiver 48 b of the photodetector 48 are disposed so as to faceeach other on the path of the central hole (d) of the optical disc D.Consequently, when the disc tray 17 is moved from the ejection positionto the stock position, the detection light is interrupted once by theinformation recording face of the optical disc D. When the detectionlight reaches the central hole (d) after the information recording face,the detection light is detected again by the photoreceiver 48 b.

[0141] Irrespective the diameter, 12 cm or 8 cm, of the optical disc D,the presence or absence of the optical disc D can be accurately andcertainly determined by the photodetector 48. For example, in the casewhere the optical disc D of 8 cm is placed off the small diameter recess30 b of the disc placement part 30, when the information recording faceof the optical disc D is positioned in a position where the detectionlight passes, the detection light interrupted state continues in thestock position and the detection light cannot be received by thephotoreceiver 48 b. By detecting the abnormal state of the photoreceiver48 b, the photodetector 48 can detect the off-state of the optical discD.

[0142] When the disc tray 17 is moved rearward passing the stockposition by the rotational force of the central feed gear 44 and therear part of the rack 39 comes into engagement with the rear feed gear63, the disc tray 17 is moved by the rotational force of the central andrear feed gears 44 and 63. After that, when the disc tray 17 is moved bya predetermined distance, the central feed gear 44 is apart from therack 39 and the disc tray 17 is moved by only the rotational force ofthe rear feed gear 63.

[0143] As a result, as shown in FIG. 10, when the optical disc D placedon the disc tray 17 is moved to the position (play position) where theit is loaded to the disc loading unit as a recording and/or reproducingunit, the optical disc D in the play position is detected by the frontand rear detection arms 91 and 92 and the detection switches 22 c and 22d attached to the rear mount base 90. On the basis of the detectionsignal, the driving motor 61 is stopped.

[0144] Also in the case where the disc tray 17 is moved from the stockposition to the play position, the presence/absence of the optical discD is tested by the photodetector 48 (FIGS. 23D to 23F). To be specific,the detection light emitted from the light emitting device 48 a andreceived by the photoreceiver 48 b is first interrupted by theinformation recording face of the optical disc D when the disc tray 17is moved toward the play position. Then, the detection light isinterrupted by the under face of the disc placement part 30 and is notreceived by the photoreceiver 48 b.

[0145] After that, the detection hole 36 opened in the disc placementpart 30 reaches the axis of the detection light (FIG. 23E) and thedetection light enters the detection hole 36. When the optical disc D isplaced in the disc placement part 30, the detection light iscontinuously interrupted by the information recording face. The presenceof the optical disc D can be therefore known according to theinterrupting state. On the other hand, when no optical disc D is placedin the disc placement part 30, the detection light passing through thedetection hole 36 is detected by the photoreceiver 48 b. Consequently,the absence of the optical disc D in the disc placement part 30 can beknown.

[0146] Such an operation of detecting the optical disc D by thephotodetector 48 is similarly performed when the disc tray 17 is movedfrom the play position to the stock position. When the disc tray 17 ismoved both from the stock position to the play position and from theplay position to the stock position, the presence or absence of theoptical disc D on the disc tray 17 can be detected.

[0147] Subsequently, in the play position, the chucking operation ofloading the optical disc D onto the turntable 33 and fixing it isperformed. The operation of chucking the optical disc D is started bythe activation of the cam driving mechanism 97.

[0148] As shown in FIGS. 17 and 19, the driving motor 101 of the camdriving mechanism 97 is driven and the rotational force of the drivingmotor 101 is transmitted from the driving pulley 101 a to the cam gear95 a via the rubber belt 68 d, driven pulley 100 b, driving gear 100 a,large diameter part 99 b of the intermediate gear, small diameter part99 a of the intermediate gear, and output gear 98. When the cam gear 95a is consequently rotated, the cam pin 94 moves along the lowerhorizontal part 96 c of the cam groove 96 toward the inclined part 96 aby the rotation of the cam groove 96.

[0149] After the cam pin 94 enters the inclined part 96 a, it isgradually pushed up along the inclined part 96 a and moved to an upperpart. The swing frame 83 is swung upward around the swing shaft 83 b asa center in accordance with the lifted amount of the cam pin 94. At thistime, by the upward swing of the swing frame 83, the spindle motor 87supported by the swing frame 83 via the sub-chassis 86 is graduallypushed up and the turntable 33 fixed to the rotary shaft is inserted tothe open hole 34 formed in the almost center of the disc tray 17.

[0150] At this time, the turntable 33 approaches the optical disc Dplaced on the disc placement part 30 from the below and the centralprojection is fit in the central hole (d). In the state where it is fitin the central hole (d), the turntable 33 pushes up the optical disc D.After that, when the cam pin 94 reaches the upper end of the inclinedpart 96 a of the cam groove 96, the optical disc D loaded on theturntable 33 becomes almost horizontal. Then the optical pickup device14 moves the optical disc D on the disc tray 17 to the position wherethe optical disc D is lifted from the disc placement part 30.

[0151] The disc damper 89 disposed above the turntable 33 is attractedby the turntable 33 by the attracting force of the magnet in theturntable 33. This corresponds to a chucked state shown in FIG. 11. Theoptical disc D is sandwiched from the upper and lower sides by theturntable 33 and the disc clamper 89 and the operation of chucking theoptical disc D is executed.

[0152] At this time, when the swing frame 83 is lifted to a certaindegree, as shown in FIG. 18, the operation arm 83 a comes into contactwith the movable gear 82 from below and pushes up the movable gear 82.As a result, the engagement between the movable gear 82 and the largediameter part 80 a of the elevating gear 80 is cancelled and the powertransmitting path to the feed gear 63 is interrupted. Consequently,although the rear feed gear 63 meshes with the rack 39 of the disc tray17, the rotation of the rear feed gear 63 is prevented and the stillstate of the disc tray 17 can be assured.

[0153] Simultaneously, the lock pin 117 provided on the top face of theswing frame 83 is inserted to the lock hole 42 formed in the disc tray17. The disc tray 17 carried to the disc loading part is locked in theloading position by the swing frame 83 moved to the lifting position. Asa result, the movement in the carrying direction of the disc tray 17 isprevented. In addition to the means for interrupting the powertransmitting path, the movement of the disc tray 17 is prevented morecertainly and the secure still state can be assured.

[0154] Further, when the cam pin 94 enters the upper horizontal part 96bof the cam groove 96, the driving of the cam driving motor 101 isstopped and the rotation of the cam member 95 is stopped. At this time,the optical head 14c mounted on the carriage 14 a of the optical pickupdevice 14 enters the open hole 34 of the disc tray 17 and the objectivelens 14 b is positioned close to the information recording face of theoptical disc D. Around this time, the spindle motor 87 is driven and theoptical disc D chucked on the turntable 33 is rotated at predeterminedspeed (for example, constant linear velocity).

[0155] After that, the optical pickup device 14 is moved in the radialdirection of the optical disc D and the optical head 14 c writes aninformation signal onto the information recording face of the opticaldisc D or reads the information signal which has been already recorded.In such a manner, the recording or reproduction of information by theoptical pickup device 14 is executed.

[0156] When a desired tray operation switch is operated either to selectand eject the disc tray 17 positioning in the fourth or lower shelf ofthe tray stocker 12, or to select and exchange one of the other fourdisc trays 17 during reproduction of information, the cam gear 95 a isslightly rotated on the lower horizontal part 96 c or upper horizontalpart 96 b. At this time, since the cam pin 94 is held in the upperhorizontal part 96 b or lower horizontal part 96 c, its horizonal stateor inclined state is held without causing a change in the posture of theswing frame 83 by the rotation of the cam member 95.

[0157] As a result, the projection 40 a of the slider 40 fit in the endface cam 95 b of the cam member 95 is guided and slides along the camface. The slider 40 is accordingly moved toward the rotation center ofthe cam member 95 while being guided by the attaching screws 102 a and102 b inserted in the two long holes 40 b and 40 c. Similarly, the twooperation loops 103 a and 103 b are moved to the cam member 95 side,thereby moving the operation pins 73 e and 78 d toward the inside.

[0158] As a result, the swing arm 73 swings counterclockwise in FIG. 10by the movement of the operation pin 73 e and the central feed gear 44is moved outward. By the movement of the operation pin 78 d, the steppedswitching lever 78 swings clockwise in FIG. 17. Since the arm 78 c ofthe stepped switching lever 78 is similarly swung clockwise, theelevating gear 80 slides from the upper face 78 f as the first positionalong the inclined face 78 e to the lower face 78 g as the secondposition.

[0159] As illustrated in FIGS. 18 and 21, the elevating gear 80 is movedwhile assuring the engagement between the large diameter part 80 a ofthe elevating gear 80 and the small diameter part 76 b of theintermediate gear 76, and the small diameter part 80 b comes intoengagement with the Geneva pin gear 110. As illustrated in FIG. 17, therotational force of the driving motor 61 is therefore transmitted fromthe intermediate gear 76 via the elevating gear 80 to the Geneva pingear 110. As shown in FIG. 20, the rotational force of the Geneva pingear 110 is transmitted from the cam pin 110 b via the cam groove 111 ato the Geneva groove gear 111.

[0160] The rotational force of the Geneva groove gear 111 is transmittedfrom the gear part 111 c to the drive gear 112 via the large diameterpart 112 a. The rotational force of the drive gear 112 is transmittedfrom its small diameter part 112 b to the rack 57 of the sliding member53. The sliding member 53 accordingly moves toward the optical pickupdevice 14 which is positioned behind the sliding member 53.

[0161] At this time, the guide pins 50, 50 fixed to the tray stocker 12are slidably fit in the stairlike cam grooves 58, 58 for elevationformed in the sliding member 53 and, as shown in FIGS. 4 and 7, theguide pins 50, 50 are movable only in the vertical direction along thevertical grooves 26, 26 formed in the chassis 11. Consequently, when thesliding member 53 is moved toward the optical pickup device 14, theguide pins 50, 50 are pushed upward by being guided by the cam grooves58, 58 for elevation.

[0162] The tray stocker 12 supported by the four guide pins 50, 50 ispushed upward in the direction almost parallel to the stack direction ofthe tray stocker 12 while being held in the almost horizontal state. Atthis time, the five horizontal parts 58 a which are parallel to eachother of the cam grooves 58, 58 for elevation are formed incorrespondence with the five tray housing parts of the tray stocker 12.For example, when the guide pins 50, 50 move from the lowermosthorizontal part 58 a to the third horizontal part 58 a, the tray stocker12 is lifted by an amount of two stages and the tray housing partpositioning at the third stage from the top is moved to the height sameas that of the tray insertion/ejection port 15.

[0163] In such a state, by making the disc tray 17 at the third stageprotrude from the tray insertion/ejection port 15, even duringreproduction of information, the desired disc tray 17 is ejected and theoptical disc D can be exchanged or newly loaded. The ejection stateduring reproduction is shown in FIG. 12. In FIG. 12, the disc tray 17housed in the lowermost tray housing part of the tray stocker 12 isejected from the tray insertion/ejection port 15.

[0164] By either pushing the ejected disc tray 17 or operating thecorresponding tray operation switch, the ejected disc tray 17 is housedinto the tray stocker 12. It makes the elevating operation of the traystocker 12 possible. For example, the tray stocker 12 is moved to ejectthe second or fourth disc tray 17 and a new optical disc D is insertedor an exchanging work of the optical disc D can be performed. Anoperation of lowering the tray stoker 12 to the lowermost stage andreturning the disc tray 17 on which the optical disc D to which areproducing operation until then has been stopped and which has beenreturned is placed to the fifth tray housing part can be performed.

[0165] After that, when the operation of reproducing music play or thelike is finished, the driving of the spindle motor 87 is stopped.Simultaneously, the cam driving motor 101 of the cam driving mechanism97 is driven to rotate the cam member 95. It makes the cam pin 94 comeoff from the upper horizontal part 96 b of the cam groove 96 and movealong the inclined part 96 a to the lower horizontal part 96 c. As aresult, the posture of the swing frame 83 is changed from the liftedposition where the swing frame 83 is in an almost horizontal state shownin FIG. 11 to the lowered position where the swing frame 83 is in theinclined state shown in FIG. 6.

[0166] At this time, by the downward swing of the swing frame 83, theturntable 33 is gradually lowered and is detached from the disc clamper89 against the attracting force of the magnet. The chucking of theoptical disc D by the turntable 33 and the like is accordingly cancelledand the optical disc D is left on the disc placement part 30 of the disctray 17 carried to the loading position.

[0167] The disc tray 17 can be therefore carried from the play positionto the stock position of the fifth tray housing part in the tray holder12. When the disc tray 17 is moved forward and carried to the trayhousing part of the tray stocker 12, the driving of the driving motor 61is stopped. As a result, the disc recording/reproducing apparatus 10 isreturned to the original stock position shown in FIGS. 5 and 6.

[0168] Although the description has been given above, the invention isnot limited to the foregoing embodiment. For example, although the casewhere the invention is applied to the disc recording/reproducingapparatus capable of performing both recording and reproduction by usingan optical disc as a disc-shaped recording medium has been described,obviously, the invention can be applied to an apparatus dedicated torecording or reproduction. Further, a magneto optic disc, a magneticdisc, and the like can be used as the disc-shaped recording media.Further, although the case where the five disc trays are stacked hasbeen described in the embodiment, the number of disc trays may be fouror less or six or more.

[0169] The case where the optical disc is chucked by changing theposture of the turntable by swinging the swing frame around the swingshaft as a center has been described in the above-mentioned embodiment.Besides, for example, the disc-shaped recording medium can be alsochucked by the advancing/retreating movement of the turntable side bymoving the swing frame in the direction which perpendicularly crossesthe moving direction of the disc tray. As mentioned above, the inventioncan be variously modified without departing from its spirit and scope.

1. An apparatus for recording and/or reproducing a disc-shaped recordingmedium, comprising: a plurality of placement members on each of which adisc-shaped recording medium is placed; a housing unit in which theplacement members are stacked and housed; an elevating mechanism forelevating the housing unit in the direction almost parallel to the stackdirection of the placement members; a recording and/or reproducing unitfor recording or reproducing the disc-shaped recording medium; acarrying mechanism for carrying at least one of the plurality ofplacement members between a position where the placement member ishoused in the housing unit and a position where the disc-shape recordingmedium placed on the placement member is loaded to the recording and/orreproducing unit; a driving source for driving both the carryingmechanism and the elevating mechanism; and a switching mechanism forselectively supplying a driving force from the driving source to thecarrying mechanism and the elevating mechanism.
 2. An apparatus forrecording and/or reproducing a disc-shaped recording medium according toclaim 1, wherein a rack part is formed in the placement member, thecarrying mechanism has a feed gear which comes into engagement with therack part and an arm to which the feed gear is rotatably attached, andthe switching mechanism swings the arm so that the feed gear isdisengaged from the rack part when the elevating mechanism is driven. 3.An apparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 2, wherein the carrying mechanism has not onlythe feed gear but also another feed gear for carrying the placementmember, the switching mechanism has a moving gear which is moved betweenfirst and second positions, a driving force from the driving source istransmitted to the another feed gear when the moving gear is in thefirst position, and the driving force from the driving source istransmitted to the elevating mechanism when the movable gear is in thesecond position.
 4. An apparatus for recording and/or reproducing adisc-shaped recording medium according to claim 3, wherein the elevatingmechanism has a slider for elevating the housing unit.
 5. An apparatusfor recording and/or reproducing a disc-shaped recording mediumaccording to claim 4, wherein the elevating mechanism has a Geneva gearwhich is rotated by the moving gear and moves the slider.
 6. Anapparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 3, further comprising a cam member, whereinthe switching mechanism further includes a switching slider driven bythe cam member, and the switching slider is moved by the cam member,thereby swinging the arm.
 7. An apparatus for recording and/orreproducing a disc-shaped recording medium according to claim 6, whereinthe switching mechanism further comprises a lever, the lever is swungwhen the switching slider is moved to thereby move the moving gear tothe second position.
 8. An apparatus for recording and/or reproducing adisc-shaped recording medium according to claim 6, wherein the recordingand/or reproducing unit is moved to a position where the disc-shapedrecording medium on the placement member is lifted from the placementmember by the cam member and a position lower than the placement member.9. An apparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 8, wherein when the recording and/orreproducing unit is moved to the lifted position, the driving force fromthe moving gear to the another feed gear is interrupted.
 10. Anapparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 9, wherein the carrying mechanism has amovable gear which is disposed between the another feed gear and themoving gear and is moved by the recording and/or reproducing unit. 11.An apparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 8, wherein the placement member is locked inthe loading position when the recording and/or reproducing unit is movedto the lifted position.
 12. An apparatus for recording and/orreproducing a disc-shaped recording medium according to claim 11,wherein the placement member is locked in the loading position by therecording and/or reproducing unit moved to the lifted position when therecording and/or reproducing unit is moved to the lifted position. 13.An apparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 12, wherein a fitting projection is formed ineither the recording and/or reproducing unit or the placement member anda part to which the fitting projection is fit is formed in the other oneof them.
 14. An apparatus for recording and/or reproducing a disc-shapedrecording medium, comprising: a plurality of placement members on eachof which a disc-shaped recording medium is placed; a housing unit inwhich the placement members are stacked and housed; an elevatingmechanism for elevating the housing unit in the direction almostparallel to the stack direction of the placement members; a recordingand/or reproducing unit for recording or reproducing the disc-shapedrecording medium; a carrying mechanism for carrying one of the pluralityof placement members among a position where a disc-shaped recordingmedium can be placed or ejected to/from the placement member, a positionwhere the placement member is housed in the housing unit and a positionwhere the disc-shape recording medium placed on the placement member isloaded to the recording and/or reproducing unit; a driving source fordriving both the carrying mechanism and the elevating mechanism; and aswitching mechanism for selectively supplying a driving force from thedriving source to the carrying mechanism and the elevating mechanism.15. An apparatus for recording and/or reproducing a disc-shapedrecording medium according to claim 14, further comprising aphotodetector for detecting the presence/absence of the disc-shapedrecording medium on the plurality of placement members housed in thehousing unit.
 16. An apparatus for recording and/or reproducing adisc-shaped recording medium according to claim 15, wherein thephotodetector detects the presence/absence of the disc-shaped recordingmedium on the placement member during the placement member is moved fromthe position where the disc-shaped recording medium can be placed orejected to the position where the placement member is housed.
 17. Anapparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 15, wherein the photodetector detects thepresence/absence of the disc-shaped recording medium on the placementmember during the placement member is moved from the housing position tothe loading position.
 18. An apparatus for recording and/or reproducinga disc-shaped recording medium according to claim 14, wherein a rackpart is formed in the placement member, the carrying mechanism has afeed gear which comes into engagement with the rack part and an arm towhich the feed gear is rotatably attached, and the switching mechanismswings the arm so that the feed gear is disengaged from the rack partwhen the elevating mechanism is driven.
 19. An apparatus for recordingand/or reproducing a disc-shaped recording medium according to claim 18,wherein the carrying mechanism has not only the feed gear but alsoanother feed gear for carrying the placement member, the switchingmechanism has a moving gear which moves between first and secondpositions, a driving force from the driving source is transmitted to theanother feed gear when the moving gear is in the first position, and thedriving force from the driving source is transmitted to the elevatingmechanism when the another feed gear is in the second position.
 20. Anapparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 19, wherein the elevating mechanism has aslider for elevating the housing unit.
 21. An apparatus for recordingand/or reproducing a disc-shaped recording medium according to claim 20,wherein the elevating mechanism has a Geneva gear which is rotated bythe moving gear and moves the slider.
 22. An apparatus for recordingand/or reproducing a disc-shaped recording medium according to claim 19,further comprising a cam member, wherein the switching mechanism furtherincludes a switching slider driven by the cam member, and the switchingslider is moved by the cam member, thereby swinging the arm.
 23. Anapparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 22, wherein the switching mechanism furtherincludes a lever, and the lever is swung when the switching slider ismoved, thereby moving the moving gear to the second position.
 24. Anapparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 22, wherein the recording and/or reproducingunit is moved to a position where the disc-shaped recording medium onthe placement member is lifted from the placement member by the cammember and a position lower than the placement member.
 25. An apparatusfor recording and/or reproducing a disc-shaped recording mediumaccording to claim 24, wherein when the recording and/or reproducingunit is moved to the lifting position, the driving force from the movinggear to the another feed gear is interrupted.
 26. An apparatus forrecording and/or reproducing a disc-shaped recording medium according toclaim 25, wherein the carrying mechanism has a movable gear which isdisposed between the another feed gear and the moving gear and is movedby the recording and/or reproducing unit.
 27. An apparatus for recordingand/or reproducing a disc-shaped recording medium according to claim 24,wherein the placement member is locked in the loading position when therecording and/or reproducing unit is moved to the lifting position. 28.An apparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 27, wherein the placement member is locked inthe loading position by the recording and/or reproducing unit moved tothe lifting position when the recording and/or reproducing unit is movedto the lifting position.
 29. An apparatus for recording and/orreproducing a disc-shaped recording medium according to claim 28,wherein a fitting projection is formed in either the recording and/orreproducing unit or the placement member and a part to which the fittingprojection is fit is formed in the other one of them.
 30. An apparatusfor recording and/or reproducing a disc-shaped recording mediumaccording to claim 14, wherein the switching mechanism supplies adriving force from the driving source selectively from the carryingmechanism to the elevating mechanism when the housing unit is moved inthe vertical direction and the carrying mechanism carries any of theplurality of placement members from the housing unit during thedisc-shaped recording medium is recorded or reproduced by the recordingand/or reproducing unit.
 31. An apparatus for recording and/orreproducing a disc-shaped recording medium, comprising: a plurality ofplacement members on each of which a disc-shaped recording medium isplaced; a housing unit in which the placement members are stacked andhoused; a recording and/or reproducing unit for recording or reproducingthe disc-shaped recording medium; a moving mechanism for moving therecording and/or reproducing unit from a position where the disc-shapedrecording medium on the placement member is lifted from the placementmember and a position lower than the placement member; a carryingmechanism for carrying one of the plurality of placement members betweena position where the placement member is housed in the housing unit anda position where the disc-shape recording medium placed on the placementmember is loaded to the recording and/or reproducing unit; a drivingsource for driving the carrying mechanism; and a transmitting mechanismfor interrupting transmission of a driving force from the driving sourcewhen the recording and/or reproducing unit is moved to the liftingposition.
 32. An apparatus for recording and/or reproducing adisc-shaped recording medium according to claim 31, wherein the carryingmechanism has at least one feed gear for carrying the placement member,the transmitting mechanism has a movable gear to which a driving forcefrom the driving source is transmitted, and engagement between the feedgear and the movable gear is cancelled when the recording and/orreproducing unit is moved to the lifting position.
 33. An apparatus forrecording and/or reproducing a disc-shaped recording medium according toclaim 32, wherein the placement member is locked in the loading positionwhen the recording and/or reproducing unit is moved to the liftingposition.
 34. An apparatus for recording and/or reproducing adisc-shaped recording medium according to claim 33, wherein theplacement member is locked in the loading position by the recordingand/or reproducing unit moved to the lifting position when the recordingand/or reproducing unit is moved to the lifting position.
 35. Anapparatus for recording and/or reproducing a disc-shaped recordingmedium according to claim 34, wherein a fitting projection is formed ineither the recording and/or reproducing unit or the placement member anda part to which the fitting projection is fit is formed in the other oneof them.
 36. An apparatus for recording and/or reproducing a disc-shapedrecording medium according to claim 31, wherein the carrying mechanismhas not only the feed gear but also another feed gear for carrying theplacement member, the moving mechanism has a cam member for moving therecording and/or reproducing unit between the lifting position and thelowered position and a movable gear moving between first and secondpositions, and the moving gear transmits a driving force from thedriving source is transmitted to the another feed gear when the movinggear is in the first position.
 37. An apparatus for recording and/orreproducing a disc-shaped recording medium according to claim 36,further comprising an elevating mechanism for elevating the housing unitin a direction which is almost in parallel to the stack direction of theplacement members, and a diving force from the driving source istransmitted when the moving gear is in the second position.